Zinc salt deicers



United States Patent Ufhce 3,010,811 Patented Nov. 28, 1961 3,010,811 ZINC SALT DEICERS John J. Giammaria, Woodbury, N.J., assignor to Socony Mobil Oil Company, Inc., a corporation of New York No Drawing. Filed Nov. 2, 1959, Ser. No. 850,085 3 Claims. (Cl. 44-68) This invention relates to gasoline compositions adapted to improve the operation of internal combustion engines. It is more particularly concerned with motor fuels that provide improved engine operation under cool, humld weather conditions.

As is well known to those skilled in the art, frequent stalling of automobile engines, especially during the warmup period, has been a common occurrence. This 'difiiculty is most pronounced in postwar cars having automatic transmissions and a consequent limit on the muimum permissible idle speed, although it also occurs in cars without automatic transmissions. Stalling of this type, of course, is a definite safety hazard, as well as a decided inconvenience in frequent restarting of the engme.

' It is now recognized that stalling during the warmup period is attributable to the formation of ice on the throttle plate and the carburetor barrel near it. The

water which forms the ice does not come from the gasoline, i.e., as entrained .water, but from the air that enters the carburetor. As has been mentioned hereinbefore, stalling generally occurs in cool, humid weather,

when the temperatures are above about 30 F. and below about 60, F. and the relative humidity is about 65 percent and higher, up tolO percent. The most critical conditions are temperatures of 35-40 F. and 100 percent relative humidity.

As the gasoline evaporates in the carburetor, it reduces the temperature of the surrounding metal by as much as 40 F. Moisture in the incoming air comes in contact with these parts and begins to build up ice on the throttle plate and in the carburetor barrel. The more moist this air is, the greater the buildup of ice. Then, when the engine is idled, the throttle plate closes and the'ice chokes ofi the normal small flow of air through the small clearance between the throttle plate and the carburetor wall. 'This causes the engine to stall. The engine can usually be restarted when the heat from the exhaust manifold melts the ice sufiiciently. How- 'ever,'stalling will continue 'until the engine is completely warmed up.

Gasoline is amixture' of hydrocarbons having an initial boiling point falling between about 75 F. and about 135 F. and an end-boiling point falling between about gasoline, of course, reflects on its volatility. Thus, a higher boiling gasoline will be less volatile and give less stalling difiiculty. In modern engine operation, however, control of stalling by means of decreased volatility is not feasible, because other performance characteristics are affected.

It has now been found that stalling during engine warmup can be overcome simply and economically. It has been discovered that small amounts of certain zinc salts of partial esters of phosphoric acid or thiophosphoric acid, when added to motor gasoline, will overcome stalling difficulties attributable to carburetor icing.

Accordingly, it is an object of this invention to provide an improved motor fuel. Another object is to provide a motor fuel adapted to prevent stalling during engine warmup in cool, humid weather. A specific object is to provide an antistall gasoline containing the zinc salt of certain mixed partial esters of phosphoric acid or thiophosphoric acid. Other objects and advantages of this -250- F. and about 450 F. The boiling range of the about one percent, by weight, of the gasoline.

invention will become apparent to those skilled in the art, from the following detailed description.

In general, this invention provides a motor gasoline containing a small amount, suflicient to inhibit stalling, of the zinc salt of mixed partial esters of phosphoric acid or of thiophosphoric acid, and particularly the zinc salt of mixed mono(lower-alkyl penyl) and di(loweralkyl phenyl) esters of phosphoric acid.

The zinc salts contemplated herein are readily prepared by methods known in the art. The salt can be prepared from any mixed ester of phosphoric acid or of thiophosphoric acid. Esters of phosphoric acid can be prepared by methods known in the art. A typical procedure involves reacting P 0 with straight or branched chain alcohols having 1 to 18 carbon atoms,

such as methanol, propanol, butanol, octanol, Z-ethylhexanol, dodecanol, and oleyl alcohol; or with alkylphenols, such as cresol, octylphenol, diamylphenol, and waxphenol. The preferred class of mixed partial esters includes the mixed mono(loWer-alkyl phenyl) and di- (lower-alkyl phenyl) ester of orthophosphoric acid. These esters are prepared, suitably, by reacting loweralkyl phenols (e.g., cresol, amylphenol, diamylphenol, butylphenol) with P 0 in' a molar ratio of 3:1, respectively. The conditions and method of carrying out this reaction are clearly described, as for example, in United States Letters Patents Numbers.2,638,447.and 2,790,767.

The mixed partial esters of thiophosphoric acid corresponding to the aforedescribed phosphoric acid mixed esters are prepared by reacting P 8 with the alcoholsor alkylphenols. Typical methods are set forth, for vexample, in United States Letters Patent Number 2,410,650.

The zinc salt is prepared by reacting the sodium salt aqueous or alcoholic solution of zinc chloride. Another procedure is to react the partial esters directly with zinc acetate or zinc carbonate. It will be understood that the salt can be made by any method for producing neutral salts and that this invention is not to be limited to the aforementioned methods.

The amount of zinc salt of mixed alkylphenyl partial esters of phosphoric acid that is added to the motor gasoline will vary between about 0.0001 percent and In preferred practice, amounts varying between about 0.001 percent and about 0.1 percent, by weight, are used.

The anti'stall additives of the invention maybe used in the gasoline along with other antistall addition agents or other additives designed to impart other improved properties thereto. Thus, anti-knock agents, preignition inhibitors, anti-rust agents, metal-deactivators, dyes, anti- "oxidants, detergents, etc., may be present in the gasoline.

Also, the gasoline may contain a small amount, from about 0.01 percent to about 1 percent, by weight, of a solvent, oil or upperlube. Suitable oils, for example include Coastal and Mid-Continent distillate oils having viscosities within the range of from about 50 to about 500 S. U.S. at F. Synthetic oils, such as diester oils, polyalk-ylene glycols, silicones, phosphate esters, polyphenyl ethers, polypropylenes, polybutylenes and the like, may also be used.

The following examples are for the purpose of illustrating the additives of this invention and demonstrating the effectiveness thereof. This invention is not to be limited to the specific composition set forth in the example or to the operations and manipulations involved. Other materials and formulations as described hereinbetore can be used, as those skilled in the art will readily understand.

EXAMPLE 1 Three moles of diamylpheno'l (702 grams) are placed followed by several concentrations of the additive.

in a 3 liter, 3-neck'flask equipped with stirrer, thermometer and reflux condenser and heated to 100 C. One mole of P (142 grams) is added in small portions over a three hour period. The temperature is then raised to 150 C. and held for three hours. The mixture is cooled and filtered through a layer of Hi-flo clay. The acid has a neutralization number of 165. Fifty grams of this acid are dissolved in 100 grams of mineral oil having a viscosity at 100 F of 100 S.U.S. To this is added 11.6 grams of ZnCO (25% exess'). h mixture is heated at 160-170 C. for about two hours, cooled and filtered through a layer of Hi-flo clay.

Final blend contains 35.5% of the zinc salt.

The ability of an additive to inhibit stalling is demon- .strated in the following tests: 'A standard Chevrolet engine, equipped with a Holley single downdraft carburetor, was mounted in a cold room refrigerated to 45* F. A thermocouple was attached to the throttle plate shaft to record the plate temperature. A /2-inch insulating gasket was placed between the carburetor and manifold to prevent heat conduction. An asbestos sheet covered the entire manifold system to shield the carburetor from convection and radiation. "to saturate the incoming air with moisture and to cool A spray chamber and an ice tower was used the'air to about 35 F. before it entered the carburetor. In conducting a test, the engine was first run for about minutes at 2000 rpm. to bring the engine temperature to equilibrium. The engine was then shut ofi. 'When the throttle shaft temperature rose to 40 F., the engine was restarted with the idle speed set at 450 r.p.m.

so that the base fuel stalled at idle in 10 seconds or less after a run-time of to 40 seconds Run-time means the time that the engine was run at 2000 r.p.rn. before returning to idle.

All the runs were started when the throttle shaft at each run-time and averaged.

In evaluating an additive, the base fuel was first tested The system was flushed between tests with the fuel to be run next. Any improvement caused by the additive was refieoted in a longer run-time (as compared to the base fuel) to cause stalling in 10 seconds or less when the engine was idled. The more effective the additive, the

jlonger the run-time.

The gasoline used to test the additives contemplated 'hereinwas a blend of, by volume, 70 percent catalyticallycracked gasoline and percent natural gasoline. It had an -A.S.T.M. boiling range of 98 F. to 387 F -with a mid-boiling point of 194 F. Y

1 "Using this test gasoline, the salt of Example 1 was subjected to the aforedescribed stalling test. The pertinent data and test results are set forth in Table I.

Table I Concn, Run-time Compound added weight to 10 sec. percent stall time (see) None (blank fuel) 0.0 30 Example 1 0. 01

It will be apparent from the data of Table I, that the zinc salts described herein are efiective antistall additives for "gasoline. Most show an increase in run-time of 50-100 percent over the blank fuel. The material of Example 1 increases run-time by 200 percent.

Although the present invention has been described with preferred embodiments, it is to be understood that modifications and variations may be resorted to, without departing from the spirit and scope of this invention, as those skilled in the art will readily understand. Such variations and modifications are considered to be within the purview and scope of the appended claims.

What is claimed is:

1. A motor gasoline containing a small amount, sufficient to inhibit stalling, of the zinc salt of mixed mono- (lower alkyl phenyl) phosphoric acid and di(lower alkyl phenyl) phosphoric acid.

2. A motor gasoline containing between about 0.0001 percent and about 1 percent, by weight of the gasoline, of the zinc salt of mixed mono(lower alkyl phenyl) phosphoric acid and di(lower aflkyl phenyl) phosphoric acid.

3. A motor gasoline containing between about 0.001 percent and about 0.1 percent, by weight of the gasoline, of a zinc salt of mixed mono (diamylphenyl) phosphoric acid and di(diamylphenyl) phosphoric acid.

References Cited in the file of this patent OTHER REFERENCES Surface Active Agents, by Schwartz and Perry, Interscience Pub. Inc., N.Y., 1949, pp. 481-488.

Petroleum Refining with Chemicals, by Kalichevsky and Kobe, Elsevier Pub. Co., N.Y., 1956, page 480.

UNITED STATES PATENT OFFICE CERTIFICATION OF CORRECTION Patent N00 3 OlO 8ll November 28 1961 John Ja Giammaria It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column l line 33 for "10 percent" read 100 percent column 2 line 7 for penyl read phenyl Signed and sealed this 24th day of April 1962,

(SEAL) Attest:

ESTON e. JOHNSON DAVID L, LADD Attesting Officer Commissioner of Patents 

1. A MOTOR GASOLINE CONTAINING A SMALL AMOUNT, SUFFICIENT TO INHIBIT STALLING, OF THE ZINC SALT OF MIXED MONO(LOWER ALKYL PHENYL) PHOSPHORIC ACID AND DI(LOWER ALKYL PHENYL) PHOSPHORIC ACID. 